The San Francisco Maritime National Historical Park comprises educational resource buildings, historic flotilla and beach.
You can pick up a free Junior Ranger Program activity booklet at the visitor centre suitable for 5 to 12 year olds to help keep them engaged, and the centre itself has some fascinating displays on the area's martime heritage.
Out by the pier you can view the park's collection of floating historic ships and get some great views of the Golden Gate Bridge.
There are numerous ranger led tours both around the park and on several of the boats, plus activities and events held. The beach at aquatic cove is nicely sandy.